Not technically armor, but a monk's belt has no ACP, ASF, or Max Dex, and the potential bonus to AC granted is infinite, so long as you boost your Wis.
Also, greater/mage armor and inertial armor.
Imagine a venerable (+3 Wis) anthropomorphic bat (+6 Wis) with a starting Wisdom of 27. Take levels in psychic warrior, or ardent (+5 Wis through HD upgrades), +6 periapt (or belt of magnificience), and a tome (another +5) for a final Wis of 42. That alone is a +16 to AC, which stacks with a fully-augmented inertial armor (which is an additional +15, if Overchanneled). There's no Max Dex involved, so we can get another +10 out of it easily.
Of course, AC stops mattering much around level 7 or so, which is when you should focus on investing in miss chances and simply not being reachable.